Poled-polymer systems

The general constraints for the design of any dyes for ADPM SHG in poled polymer systems rapidly narrow the choice of chromophores. The dyes should be overall charge neutral (to facilitate poling) and highly soluble in polymer matrices. The first excited electronic state should be well separated from higher energy states for two reasons (1) since the vibronic envelope associated with an... 

In the view of the practical use, polymeric materials are expected to overcome the disadvantages of organic molecular crystals in mechanical properties and processability. Most polymers are usually in a symmetric structure as a whole, so they should be considered as third-order rather than second-order NLO materials, except for poled polymer systems. 

High-performance Electooptic Poled-polymer Systems... 

In addition to solution measurements, several bulk measurements have been made on ferrocene chromophores incorporated into poled polymer films." These measurements have shown that there are no special problems associated with poling ferrocene chromophores. The best bulk performance achieved for a ferrocene-based polymer material was an EO coefficient, of 25pmV (1,300 nm) for a film of 18 incorporated at 20 wt.% into amorphous polycarbonate " this is not, however, competitive with the performance of state-of-the-art all-organic poled polymer systems. In some cases, the chromophores have been covalently linked to the polymer chain. Bulk SHG measurements have also been made on self-assembled Langmuir-Blodgett films incorporating ionic ferrocene-based chro-... 

Burland DM, Miller RD, Walsh CA. 1994. Second order nonlinearity in poled polymer systems. Chem Rev 94(1) 31 75. 

D.M. Burland, R.D. Miller, C.A. Walsh, Second-Order Nonlinearity in Poled Polymer Systems, Chem. Rev. 94 (1994) 31. 

Burland D.M., Miller R.D., Walsh C.A. Second-order nonlinearity in poled polymer system. Chem. 

Amoco Ultradel 9000D aromatic polyimides (Fig. 2, below) are a family of 7-butyrolactone (GBL) soluble, fully imidized, fluorinated polyimides developed for integrated optical applications. Thermal or photochemical cross-linking imparts aTg approaching 400 °C and provides stability for poled polymer systems. Excellent optical transparencies have also been demonstrated in these materials. 

Table 4.2 Characteristics of reported poled polymer systems...

Several types of functional decay forms have been used to describe time-dependent processes in poled polymer systems. The Kohlrausch-Williams-Watts (KWW) [72] stretched exponential function has often been used to fit the orientation decay of chromophores in polymers ... 

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